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Battery Czar

Denise Gray had to take a city bus to her first job at GM, but now she holds the company’s green-car future in her hands

13 min read
Denise Gray
Photo: Joshua Dalsimer

Carmakers really, really don’t like to take chances. Not since the earliest days of the industry have they tried to develop a new body and chassis and a new energy storage and power delivery system, all at the same time and all for the same car. Yet that’s exactly what General Motors is doing with its upcoming Chevrolet Volt extended-range electric car. And the stakes couldn’t be higher.

Caught off guard a decade ago as rival Toyota launched and then refined its hybrid-electric-drive cars, GM has struggled to catch up. Within the last year, Toyota has equaled GM’s global production—and announced the manufacture of its millionth Prius hybrid. But with the Volt and various other hybrid vehicles of its own, GM has mapped out a bold strategy that will pit it squarely against Toyota. The arena? Technology.

The executive at the center of this battle is an African-American engineer in her 40s—one of very few black women in the auto industry’s upper ranks—who didn’t even own a car when she took her first job at GM 28 years ago. Denise Gray, unofficially GM’s “battery czar,” is the company’s director of energy-storage devices. Her job is nothing less than overseeing GM’s efforts to develop a new generation of batteries that will give it an edge in electric vehicles.

At the top of her to-do list is testing and approving the battery pack for the much-touted Volt, which GM is working feverishly to release in November 2010. The clock began ticking when the first battery pack was delivered last year on 31 October and won’t stop until the first Volt rolls into a dealer’s showroom. Until then, Denise Gray will be the executive to watch in the U.S. automotive industry.

It’s hard to overstate how much GM has riding on the Volt. Decades of downsizing and dwindling North American sales have the company locked in a neck-and-neck race with surging Toyota for the title of the world’s largest car company, which GM held for 70 years. With the radical Volt, GM hopes to leapfrog its rival’s decade of experience in hybrid electric vehicles.

Technically, the two firms’ approaches to electric drives could scarcely be more different. Toyota has built more than 1 million “power-split” hybrids, which use a battery with a storage capacity of 1 to 2 kilowatt-hours to assist the gasoline engine and store energy regenerated while braking. These cars travel only 1 or 2 kilometers on pure electric power.

By contrast, the Volt is an “extended-range electric vehicle,” which will take advantage of the new large-format lithium-ion batteries just now entering the market. Its 16-kWh battery pack will give the car a pure-electric range of up to 65 km, or 40 miles, with a small gasoline engine providing another 480 km, or about 300 miles, on a single tank of fuel. That gas engine, however, won’t drive the wheels directly; it will power only a generator that recharges the batteries, which drive the electric motor that spins the wheels. The Volt will also have a plug that will let its batteries be recharged from any outlet; that’s why this kind of vehicle is also called a plug-in hybrid.

With sales of big, gas-thirsty vehicles in free fall in the United States, GM has called the Volt its most important new car program. And success or failure will hinge on those lithium-ion battery packs; if they don’t prove robust enough to last 10 years and 240 000 km (about 150 000 miles), the car will flop.

All Gray has to do is make sure GM picks the right lithium-ion system and then ensure that those battery packs are exhaustively tested. She’ll have to navigate government safety-certification requirements in multiple countries and have the packs manufactured in large quantities and to very high quality standards. She’s got two years to get it done.

Car talk surrounded Gray during her childhood in Detroit in the 1960s and 1970s. “My entire family worked in the industry,” she says. “My aunt assembled V6 engines at GM’s Livonia engine plant; my other aunt and my uncles assembled axles at GM Gear & Axle. Working for auto companies was just a part of our life.” Her mother worked at GM too, making stabilizer bars and other parts in a General Motors forge plant—some of the hottest and most grueling work in the industry. Still, even though cars were in her blood, Gray didn’t own one when she first started working at GM in 1980; she rode the city bus to her position in Warren, Mich., at the GM Technical Center.

Today, when time is tight, she flies on a GM corporate jet. And back on earth, she gets a brand-new company car every few months. These days, she’s driving a sporty Cadillac SRX crossover, after recently trading in a low-slung, V8-powered Corvette. Her smile flickers when she says, quietly but firmly, “I like to merge with pride.”

Her mother, Vernice, had moved to Detroit from Arkansas in the 1950s, seeking a job in the booming hub of the U.S. auto industry. Denise’s father left when she was five; after that Vernice worked full-time to support her children.

Gray attributes much of her own success to Vernice. “My mom is the epitome of determination to succeed,” she says. “She probably didn’t have a lot of good cards dealt to her, but she’s made the best of it. She’s an extremely hard worker and was extremely focused on taking care of her family.”

The family lived in an old frame house in Detroit, and Gray attended that city’s public schools. In middle school, a mathematics teacher impressed by her math and science abilities suggested she apply to Lewis Cass Technical High School, then Detroit’s only magnet school. The young Denise hadn’t given it much thought, but she followed the teacher’s advice and easily passed the entrance exam for admission.

At Cass, she was one of only two girls who focused on electronics. “I began quickly recognizing there’s a gender issue here,” she says. “It’s not something that girls usually go into. But it really did keep my interest.”

This being Detroit 30 years ago, autos were a core part of the curriculum. Gray reminisces fondly about learning to weld. “I remember being in the garage, learning how to use a torch,” she says. “It was neat.” She compiled a 3.86 grade point average and caught the eye of GM coordinators looking for bright students with good grades and self-starter attitudes to work half-day jobs.

“You worked with the mechanics, so you wore a uniform,” she recalls. “When I would catch the bus home, I’d have on my uniform. And the kids knew I had gone to Cass, and they were all wondering, What happened to this smart girl? ’Cause now she’s wearing a gas station attendant’s uniform!”

In 1981, after finishing high school, she went on to attend the General Motors Institute, now Kettering University, in Flint. For five years she alternated 12 weeks of studies with 12 weeks in a GM job, rotating among the divisions. She spent time in the machine shop, the foundry, the prototyping studio, and other operations—nine different assignments altogether.

In 1986, her last year at General Motors Institute, Gray met Michael Steel, an African-American design engineer a few years older than her, who worked in GM’s electric group. Steel would become her friend, boss, and mentor. “There weren’t a lot of African-American engineers then,” he recalls, “let alone female engineers, so I introduced myself.” He ended up advising her on her fifth-year thesis, on instrument clusters.

When she graduated, Steel hired her for the midsize-car division as a lead engineer. She would follow in his wake for more than a decade. For the first six years she designed electrical components for cars’ instrument panels, including such innovations as radio controls integrated into the hub of the steering wheel. She designed interior and exterior lighting, air bags, all kinds of audio equipment, and interfaces between the electrical systems of the vehicle and its engine and transmission.

Meanwhile, in 1989, Steel left the instruments group to manage the Corvette team’s electronics development lab. Gray followed him to the new team, as she did again in 1992, when Steel moved to GM’s power-train group to help develop a new generation of the company’s iconic “small block” V8 engine.

Those were the days when software-controlled electronics was supplanting older ignition systems. Ignition systems had traditionally been mechanical: a rotor inside the distributor closed a succession of circuits that caused the engine’s coil to deliver enough power to each spark plug to make it produce a spark, igniting the gasoline-air mixture already delivered into the cylinder. But with increasingly stringent emissions limits in the 1980s, only electronics could manage engines precisely enough to control the combustion adequately. The combination of controllers, sensors, and software for those systems had to be tested in a new way.

Steel put Gray in charge of developing and implementing the tests for what became the 1997 Corvette. Her team had to define and test various operating conditions the engine might face. For instance, to produce the right torque, the software algorithm that controlled the firing of the spark plugs had to “know” the position of every cylinder to fire at the optimal time. The same engine was used in three different classes of vehicles: not only the Corvette two-seat sports car but also the four-seat Camaro coupe and a range of trucks.

Once every type of use had been written down, Gray’s team developed tests that would expose the system to the extremes of each, then calculated what a satisfactory performance should be for each test. Once every test was run, the results had to be verified (were the right tests used? were the results correct? did the whole test cycle follow our procedures?) and the testing team had to officially sign off—all before the software could be released to the larger engine team.

“She was not shy about taking verification reports to the platform manager,” Steel says, grinning. Translated from the corporate jargon, that means that despite constant pressure to stay on schedule, Gray simply refused to release any software that hadn’t met the list of requirements put together by the vehicle teams. “She would offer [the manager] a conscious decision if there was a ‘Part Not Validated’ report, saying, ‘I’m not backing down, I’m going to write the report’ ” to indicate that the system had failed its tests, says Steel. Given the challenges of integrating new and often costly electronics into the complex mechanical systems of a modern engine, it was the right decision—but hardly a popular one at the time.

Slowly but surely, she built a record of technical and managerial success. And in 1995, when Steel became software manager for all the engine groups, Gray was able to take the procedures she’d developed for the small-block team and extend them throughout the power-train organization. It was her first director-level job. In GM-speak, that means she was fully responsible for all the work of both engineers and their managers toward delivering a product—in this case, engine-control software.

That engineers must rigorously validate software is hardly a revolutionary thought nowadays. Ten years ago, though, a lot of people in auto manufacturing yawned—or sneered—at the kinds of formal procedures that standardized software testing and validation require. In the car business, electronics engineers were traditionally the stepchildren of the power-train group, compared with the mechanical engineers who designed the moving parts of the engine. The EEs’ world of computer screens was foreign to the engine guys. After all, you could tell if an engine was running properly by listening to it, right? Reading through reams of printouts to figure out if something worked correctly wasn’t a popular activity.

Nonetheless, Gray persevered in her quest to integrate modern software practices into the macho world of engine development. Over and over, says Steel, she took the time to educate other managers about what her team was doing and why it benefited them. But, he says, “she was clear that it was a discussion of how they would buy in on the method—not on the fact that she was doing this” in the first place.

Gray’s reasoning and persuasiveness did the trick. “She has the tenacity of a Chihuahua,” Steel says, grinning. “She would have been a pit bull, but she’s so small…”

That inner tenacity has helped Gray overcome any opposition sparked by her sex and race. She says, diplomatically, that she tends not to notice such attitudes. “You probably have to hit me over the head with a two-by-four to tell me you don’t respect my presence there because of my being a female” or being black, she says.

Steel is less circumspect. “As a female African-American engineer and manager in a historically white male company,” he says, bias “was there, for sure. But she put her nose to the grindstone—and she gained the respect of a lot of people.” And it worked.

In 1996, employed full-time and caring for two children—she was married in 1987—she decided she needed a master’s degree to get to the next level in her career, even though she intended to stay on a technical track. She took four years to earn her master’s in engineering science remotely from Rensselaer Polytechnic Institute, in Troy, N.Y., and ended up being inspired to switch from a technical track to a managerial one. She calls the coursework “pivotal” and says, “It truly gave me insight, and I think confidence, that I could really be in—that I needed to be in—management.”

In 2000, GM promoted Gray to her first executive-level job, director of software engineering, soon followed by director of controller integration and applications. These steps on the corporate ladder took her higher than Steel, her mentor. She was responsible for all the controller systems that the group engineered for any vehicle, both the hardware and the software. These included systems for fuel delivery, ignition timing, valve opening, overall engine control, transmission shifting, and a host of others.

In 2003, Steel became manager of software at the electronics integration and software group, reporting to Gray. “She was nervous about it,” Steel recalls. “When she got the promotion,” he says, “I told her, ‘It’s been a great ride. Now it’s time to unhook your car from my train.’ ”

In 2004, Gray moved to a position overseeing all software development for the transmission group, with the same mandate: to weave systematic and consistent software development and testing procedures through the organization. Her engineering teams designed, tested, and calibrated all the software for five of GM’s range of four-, five-, and six-speed automatic transmissions.

In 2006, she began to think about her next assignment. She knew she wanted to stay in a position where she was responsible for “getting product out the door,” but she wasn’t sure where her next focus should be. And then the pieces came together. She heard that the company had created a new director position to oversee advanced battery work. It was perfect.

“I was an electrical engineer who loved chemistry in college,” she explains. “I had the vehicle systems background, power-train background; I’d worked on leading-edge software algorithms, meeting fuel economy and emissions requirements, all of that.

“I wanted it, hands down,” she says. And on 12 October 2006, she got it.

It’s good to be battery czar. The job is highly visible—as part of the core Volt team, Gray meets often with GM CEO Rick Wagoner, product guru Bob Lutz, and other top GM executives. And there’s no doubt that the job is vital to the company’s future.

That kind of responsibility can feel overwhelming at times, she says, especially considering the task she’s been given: to pack 10 years’ worth of user testing into a couple of years.

“I recognize to the nth degree the criticality of making this happen,” Gray says, as only an engineer could. “I understand what it means to the company and, quite frankly, to the industry, to our country. I understand its significance from an energy-security perspective.” And she calls the company’s support for the project nothing less than “awesome”: “They’ve said, ‘Whatever you need, Denise.’ And it’s been provided.”

She is always aware of the pressure on this highest of high-profile projects. But her preferred approach remains collaborative and calm. “I can be in command and be the quietest person in the room,” she says. Her style is to support people working together to solve problems on their own. “We’ll be better off if everyone learns how to get from point A to point B, as opposed to being told how to get from point A to point B.”

But that’s not her only mode. She recalled that recently a fellow executive criticized one of her team members for doing something he wasn’t allowed to. “I closed my book,” she says, “and said, ‘I gave that person authority to do it. You weren’t in the meeting; you have no authority to speak on this particular subject,’ and I grabbed my coat with lots of emphasis and stormed out of the room. I usually don’t do that, but the person had done that kind of thing a couple of times, so I had to come at it from a different angle to get the point across.

“The point,” she says—quietly—“was well-taken.”

Gray remains as diplomatic as she is driven. She assiduously shares information among vendors wherever possible and works hard to make sure that GM’s internal procedures don’t gum up the works, says David Vieau, CEO of A123Systems, one of two teams vying to provide advanced lithium-ion packs for the Volt battery pack. “She’s down to earth,” he says, “and direct—but reasonably so.”

Prabhakar Patil, CEO of Compact Power—part of the competing team—says Gray has insisted that any unexpected hitches or shortfalls be discussed openly, without finger-pointing or corporate self-protection. He recalls the challenges that the company faced in designing the internal cooling for the Volt pack. Other vendors might have minimized the problems to avoid scaring their client. But, emboldened by Gray’s edict, Compact Power, a U.S. subsidiary of South Korea’s LG Chem, was quick to detail its difficulties. Gray responded immediately by making several of GM’s experienced cooling-system engineers available to Compact Power. With their help, the company solved the problems and kept on schedule.

On a typical day, Gray wakes before dawn, dispatches a night’s worth of eâ’’mail on her BlackBerry, and drives her sons Taylor, 17, and Nathan, 13, to school. She gets to the office at 7:30 a.m. and starts making phone calls to Europe. She tries to be back at home by 7:30 p.m. for family dinner. After that, more e-mail.

It’s a grueling schedule, but not so grueling as it was 18 months ago, when Gray had to spend at least one week out of four visiting lithium-ion cell makers in South Korea and Japan, touring their plants, explaining GM’s needs and plans, and educating herself. Now the competition to build the Volt battery pack is down to just two teams—Germany’s Continental, using cells from A123Systems, versus Compact Power, using cells from its parent company, LG Chem. So Gray spends more time these days with GM teams throughout Michigan or in Mainz-Kastel, Germany.

“Family first, church second, work third.” Not every executive would relegate a top job at one of the world’s biggest companies to third place. But Gray is comfortable with her choices and works hard to balance the three pillars of her life. Rob Peterson, head of communications for the Volt and E-Flex programs, recalls reminding her of a presentation on the first media day of the Detroit auto show. “I’ll be there,” she said, “but it’ll have to wait until after church.”

Similarly, she works hard to attend all of her son Taylor’s high-school football games. She may be using her BlackBerry in the stands, but she’s there—and she’s probably shouting louder than anybody else.

The Gray family lives in a suburb half an hour west of Warren, Mich., where the GM Technical Center is located. Husband Kevin, whom she met while she was a General Motors Institute student in the early 1980s, works for GM as well, as a director overseeing cooling-system development. Dinner with the family is a must. Her sons do their homework at the kitchen table—and with Mom and Dad plugging away, sometimes there are four laptops going at the same time.

What’s next? “I told my boss, hopefully there are no plans to move me, because we’re just getting started,” Gray says. “We’ve got to keep thinking about what’s next, and then what’s next”—for future batteries, for her company’s role in the industry, and for increased research into advanced energy-storage systems.

GM’s surprising openness about the progress of the Volt’s development may be a good indicator of her team’s success thus far. Global automakers tend to guard technical details closely. The Volt team, by contrast, invited 80 reporters to its labs this spring and detailed the test algorithms that let them simulate 10 years of usage in only two calendar years.

And while Gray finds herself increasingly in the spotlight, it doesn’t interest her much. “In my mind, it doesn’t matter,” she says. “I haven’t earned it. I’m flattered, but it doesn’t really mean a lot until after I’ve delivered”—when that first Volt rolls off the line, probably amid more hoopla that any new GM car in 20 or 30 years.

Occasionally she’ll let herself marvel at her life and her job, with its improbable arcing ascent: “When what you’re doing is that important to the leaders of your company, it makes you feel awfully good as an engineer.”

And it is important; in fact, it’s vital. “The advanced battery team is the group that the entire Volt project hinges upon,” says Aaron Bragman, of industry analyst Global Insight, in Troy, Mich. If GM is to survive in a market that’s clamoring for high-tech mileage champs, Bragman says, “then beating Toyota to market with a plug-in hybrid is absolutely critical.”

No one is more aware of that than Denise Gray.

About the Author

JOHN VOELCKER wanted to profile Denise Gray from the first time he met her, but given Gray’s intense work schedule, it took a year to arrange an extended interview. For “Battery Czar,” they finally sat down together at a technical conference in San Diego. Right after that meeting, she climbed into a waiting sport utility and was driven to the airport, to fly back to Detroit on a GM corporate jet.

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